Steel framing systems for buildings may be assembled from structural members which are roll formed from steel strip and provided with tabs and slots so that they can be readily interfitted to form a strong frame.
The structural members may be factory produced on machinery which forms, punches and crops them to order for immediate supply and assembly into individually designed frames with virtually no wastage and with no need for stockpiling.
Machinery for production of such framing elements is disclosed in Australian Patent No. 570845 and pending Australian patent application no. 56949/90. A typical steel framing system using such elements is described in Australian Patent No. 484003. As disclosed therein, the frame is assembled by connecting structural members formed with projecting end tabs to further structural members formed with slots, by inserting the tabs through the slots of the further members and then folding the tabs laterally to prevent withdrawal.
Typically, the frame members may be produced as elongate channel-shaped members. These may have a pair of tabs projecting from each end and pairs of transverse slots punched in their connecting webs at regular intervals along their length, so that the tabs of one member can be passed through a pair of the transverse slots of a further adjoining member, at any one of a number of locations along the length of the further adjoining member. However, some of the frame members may have slots but no end tabs, and others may be formed with end tabs but no slots, for interconnection with the slotted members.